Crutch

ABSTRACT

A foldable crutch having an upper portion and a lower portion of substantially equal lengths, connecting means adapted for pivotally connecting the adjacent ends of the upper and lower portions, and a locking mechanism adapted to hold the upper and lower portions in the linearly stretched state against the pivotal movement.

BACKGROUND OF THE INVENTION

The present invention relates to a crutch.

For those who are handicapped in their lower limbs, the crutch is avital and indispensable instrument which they cannot leave even for amoment in their daily lives.

The most serious problem common to all crutched persons resides in thetrouble concerning the disposal or storage of the crutch when it is notused, rather than the difficulty in the handling of the same for thewalking or the like purposes.

Unfortunately, the modern society is leaning to exclude the crutches inits all aspects. Thus, the crutches are becoming hardly accepted.

SUMMARY OF THE INVENTION

It is therefore a major object of the invention to provide a crutchwhich can conveniently be folded into a short length when not used.

It is another object of the invention to provide a crutch having anupper and a lower portions which are pivotally secured to each other fora 180° rotation.

It is still another object of the invention to provide a crutch having amechanism for locking the upper and lower portions against the relativepivotal movement when the crutch is to be presented for use.

It is a further object of the invention to provide a crutch having alocking mechanism which can be handled without difficulty.

These and other objects, as well as advantageous features of theinvention, will become more clear from the following description ofpreferred embodiments taken in conjunction with the accompanyingdrawings in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front elevational view of a crutch in accordance with theinvention,

FIG. 2 is a side elevational view of the crutch as shown in FIG. 1,

FIG. 3 is a side elevational view of the crutch in the folded state,

FIG. 4 is a front elevational view of the crutch in the folded state,

FIG. 5 is an enlarged perspective view of the crutch in the lockedstate, specifically showing the connecting portion of the upper andlower parts of the crutch,

FIG. 6 is an enlarged perspective view of the crutch in the unlocked andslightly folded state, specifically showing the same portion as thatshown in FIG. 5,

FIG. 7 is an enlarged perspective view of the connecting portion withthe constituents of the locking mechanism removed,

FIG. 8 is an exploded perspective view of the locking mechanism, showingthe constituents of the same, and

FIG. 9 is a sectional view taken along the line IX--IX of FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings, a crutch embodying the present invention hasan upper portion 1 and a lower portion 2 of substantially equal lengths.The upper portion 1 is provided with a handle or a hand-retaining bar 3.The lower end of the upper portion 1 has a pair of forked or U-shapedportions 1a. Each U-shaped portion 1a has a groove 1b extending in thelongitudinal direction of the upper portion 1 and at a right angle tothe breadthwise direction of the latter.

On the other hand, the lower portion 2 is provided with a pair ofprojections 2a formed on its upper end. These projections 2a arereceived by the grooves 1b of corresponding U-shaped portions 1a.

As will be seen most clearly from FIG. 7, the U-shaped portion 1a andthe projection 2 have lateral extensions which are shown, in FIG. 7, toproject downwardly from the upper and lower portions 1, 2. Mutuallyaligned through bores 4 are formed in these lateral extensions of theU-shaped portions 1a and the projections 2a.

The common axis X--X of the through bores 4 extends in the breadthwisedirection of the crutch and at a right angle to the longitudinal axis ofthe crutch.

As will be seen from FIG. 2, the center X of the through bore 4 isslightly deviated outwardly from the side edges 1c, 2c of the upper andlower portions 1, 2 of the crutch.

The upper portion 1 and the lower portion 2 are pivotally connected toeach other through a rod 5 which is inserted into the through bores 4.Thus, the lower portion 2 can be swung by 180° around the axis of therod 5, from the folded position as shown in FIGS. 3, 4 in which itextends in parallel with the upper portion 1 to the stretched positionas shown in FIGS. 1, 2 in which it is linearly extended from the upperportion 1.

The arrangement is such that the ends 1d of each U-shaped portion 1aabut shoulders 2d formed at both sides of each projection 2a, when thelower portion 2 is rotated by 180° into the stretched position, therebyto prevent the lower portion 2 from being further rotated beyond 180°.It is also possible to prevent the rotation of the lower portion 2beyond 180° by the abutment of the end surface of each projection 2a andthe bottom surface of the corresponding groove 1b.

A locking mechanism generally designated at a reference numeral 6includes a locking bore 7 formed in the U-shaped portion 1a and anotherlocking bore 8 formed in the projection 2a. These locking bores 7, 8 areso arranged that they are brought into alignment with each other whenthe lower portion 2 is in the stretched position.

Guide pipes 9 are fixed to the opposing surfaces of two U-shapedportions 1a, 1a, in axial alignment with respective locking bores 7.Each guide pipe 9 slidably holds a locking pin 10. Each locking pin 10is fixed to an operation plate 11. These operation plates 11 are fixedto respective pipes 12 which are slidable along the rod 5. A collar 13is fixed by suitable means to the center of the rod 5. A coiled spring14 is disposed on each side of the collar 13. These coiled springs 14are adapted to bias respective operation plates toward the correspondingU-shaped portions 1a, so as to drive the locking pins into the lockingbores 7, 8. Two operation plates 11, 11 are spaced apart from each otherby such a distance that these operation plates can easily be broughttogether by fingers of single hand.

In use, the lower portion 2 of the crutch in accordance with theinvention is locked at the stretched position as shown in FIGS. 1 and 2,with the locking pins 10 received by corresponding locking bores asshown in FIG. 5.

For folding the crutch, two operation plates 11, 11 are brought togetherby fingers as shown in FIG. 6, so that the locking pins 10, 10 may bedisengaged at least from the locking bores 8, 8. Then, the lower portion2 is simply pivoted with respect to the upper portion 1 to the foldedposition as shown in FIGS. 3, 4.

Since the length of the crutch is reduced to half by the folding, thecrutch in the folded state can be handled quite easily and canconveniently be stored even in an extremely limited space.

Further, the folded crutch can support itself and, therefore, canconveniently be used as a temporary stool, by flattening the lower endof the crutch in the folded state as shown in FIG. 3.

Various modifications in structure and/or function may be made to thedisclosed embodiments by one skilled in the art without departing fromthe scope of the invention as defined by the claims.

What is claimed is:
 1. A crutch comprising an elongated upper portionand an elongated lower portion; connecting means for pivotallyconnecting the adjacent ends of the upper and and lower portions to eachother about a pivot axis extending substantially in the breadth-wisedirection of the crutch and substantially at a right angle to thelongitudinal axis of the crutch, the connecting means including a pairof spaced U-shaped portions formed at the end of either one of the upperand lower portions, a pair of spaced projections formed at the end ofthe other of the upper and lower portions, each of said projectionsbeing adapted to be received within a groove defined by legs of thecorresponding U-shaped portion, through bores formed in mutual alignmentin the U-shaped portions and the projections, and a rod extendingthrough the through bores so that U-shaped portions and the projectionsare pivotally connected to each other; and locking means for locking theupper and lower portions against pivotal movement, in such a stretchedstate that the lower portion is linearly extended from the upperportions, the locking means including a pair of operating platesslidably held on the rod between the U-shaped portions, locking pinsparallel to the rod and rigidly secured on the operating plates,respectively, first locking bore formed in each of the U-shaped portionsparallel to the rod, and second locking bore formed in each of theprojections, the first and second locking bores being adapted toregister and to receive one of the locking pins when the upper and lowerportions are aligned with each other.
 2. A crutch as claimed in claim 1,wherein said upper and lower portions have substantially equal lengths.3. A crutch as claimed in claim 1 further comprising a stop meansadapted to prevent said upper portion from being rotated beyond 180°around said pivot axis in relation to said lower portion.
 4. A crutch asclaimed in claim 1, wherein said locking means further comprises a pairof guides secured on the opposing surfaces of said pair of said U-shapedportions in axial alignment with said locking bores to guide saidlocking pins, respectively.
 5. A crutch as claimed in claim 4, whereinsaid locking means further comprises biasing means for biasing saidoperation plates away from each other to insert said locking pins intotheir associated locking bores.
 6. A crutch as claimed in claim 4,wherein said biasing means includes a collar secured on said rod betweensaid operating plates and a pair of coiled springs each disposed betweensaid collar and one of said operating plates.
 7. A crutch as claimed inanyone of claim 4 or claim 5 or claim 6 or claim 1 further comprisingstop means for preventing the upper portion from rotating beyond aposition in which the upper portion is in alignment with the lowerportion.
 8. A crutch as claimed in claim 7, wherein the stop meanscomprises a pair of shoulders formed on both sides of each of saidprojections and a pair of end surfaces of each of said U-shapedportions, said end surfaces being adapted to contact with said shoulderswhen said upper and lower portions are aligned with each other.
 9. Acrutch as claimed in claim 7, wherein said stop means comprises a bottomsurface of said groove of each of said U-shaped portions and an endsurface of each of said projections, said end surface being adapted tocontact with said bottom surface when said upper and lower portions arealigned with each other.